In a natural gas distribution system, gas is distributed to customers through a network of pipes. A gas meter at each customer's site measures the amount of fuel used by the customer. The gas meter is read to determine how much gas was used, and the gas company charges the customer based on the gas meter reading.
To obtain a gas meter reading, a gas company employee can observe the gas meter or, in an automated system, an automated gas meter reader can obtain the gas meter reading from the gas meter. An automated gas meter reader is a type of sensor coupled to the gas meter. The automated gas meter reader obtains meter readings from the gas meter and transmits usage data to the gas company. In one system, the automated gas meter reader wirelessly transmits usage data to a gas company employee driving along the street in a computer-equipped vehicle. With automated gas meter readers installed at each customer's site, collecting meter readings can be accomplished much faster and more economically.
In a system including sensors, such as automated gas meter readers, the sensors may be situated in locations that are not near a convenient power source. Each sensor can include its own power source, such as a battery, solar power unit or vibrational power unit, and/or each sensor may be hardwired to a power supply.
Each of these techniques for supplying power to a sensor has one or more drawbacks. The sensors may be situated in locations that do not receive enough light for solar power units or vibrations for vibrational power units. Also, vibrational power units are typically more expensive than alternative solutions. Wiring can be expensive to install, especially in facilities or houses that are already built, and batteries can discharge before the product service lifetime is over. For these and other reasons there is a need for the present invention.